I actually think this is the best version they've done so far in regards to Slayers. While it is an upscale, and like all these upscales some detail has been lost. The edges from what I can tell when viewing seem a bit sharper, and the colours are no longer washed out making it quite enjoyable when watching.
If you can pick this up for around 30 euros, and are willing to either mux in the dub, or attach subtitles. I find the set not to be that bad. Its about the same as what Japan is currently doing (The ghosting from what I can tell got introduced into the DVD master by JP so its not disappearing)
Some episodes seemed kind of bright, but its hard to compare that to the US DVD due to the interlacing and overall kind of naff picture, but I'm happy overall with this.